In making electrical interconnections along the edge of a circuit board it is important to make good electrical contact with conductive areas on boards that max vary in thickness over a range of tolerances. Further, it is generally desirable to have a connector that has essentially zero insertion force to minimize wear of both the contacts and the conductive areas on the board. These factors are even more critical when one considers the necessity for providing a plurality of contacts on close centerline spacing. Furthermore, the close centerline spacing of the contacts require that the terminal members be relatively thin and thus they are more susceptible to damage than terminal members that are thicker. It is desirable, therefore, to provide means for protecting the terminal members and particularly the contact surface of the terminal members from interfacing the board while the connector and board are moved into position for electrical interconnection.
In today's electronic equipment a circuit board may be mounted in a piece of equipment and numerous cables may be required to attach along an edge of such a board. Connectors are terminated to these electrical cables having a plurality of conductors arranged as discrete wires or ribbon cable or the like. Preferably the connector is one which essentially requires zero insertion force and can be rotatably moved from a first to a second position to engage the conductive pads along the edge of the board. It is further desirable to have a connector that has a minimum number of parts and does not require a separate camming mechanism.
U.S. Pat. No. 3,848,952 discloses a zero insertion force card edge connector having a plurality of connector spring contacts mounted in the housing, the spring contacts providing for adjustment in both the X and Y direction.
Furthermore, it is also desirable to have a board edge electrical connector that is suitable for use with boards made of various materials such as plastic, ceramic coated dielectric or dielectric coated steel.